Safety effects of maintenance treatments to improve pavement condition on two-lane rural roads — insights for pavement management

Abstract

The research used data from two-lane rural roads in Ontario, Canada to evaluate the change in safety following maintenance treatments to improve pavement condition as measured by International Roughness Index (IRI). The state-of-the-art empirical Bayes (EB) before-after methodology was applied to estimate the effects on crashes, separately for arterial and collector roads. The results indicate statistically significant reductions (P < 0.05) in all crashes and property damage only (PDO) crashes of approximately 5% and 7%, respectively, for arterial roads and approximately 11% and 13% for collector roads. For fatal plus injury (FI) crashes, there were small, statistically insignificant changes for the two road types. The results provide interesting, and sometimes counterintuitive insights for those planning maintenance treatments to improve IRI. In sum, the results suggest that consideration should be given to designing and planning pavement maintenance treatments on a site-by-site basis, and, in so doing, to optimize the IRI levels and safety effects that may be accomplished with specific treatments.